Issue when CEP is used right after installation

I got an issue with NIK 5.1 (in demo mode) on macOS 12.5 on iMac 2019

This is what I did

  1. Installed Nik Collection with an admin user account: OK

  2. Launched all apps standalone: OK

  3. Installed Nik Collection with a non-admin user account: OK

  4. From Lightroom Classic, I sent a TIFF image to open as smart object in Photoshop: OK

  5. In PS, I launched CEP and applied a filter → ISSUE: Thumbnails were not rendered reliably, they took a long time to appear, went away and came back only partially after a few minutes:

  6. doing steps 4 and 5 with a CR2 file did NOT show the issue

  7. doing steps 4 and 5 with said TIFF again, did NOT reproduce the issue

Note: The TIFF was initially created by the Nik Plugin in a test I did between steps 3 and 4, settings were ProPhotoRGB and 240 ppi.